1. Phone Call
2. HR Interview
3. 2 hour Technical Interviews
I advice you to be prepared for lost of questions from STL- Know how to work with linked list and string from STL. More function you know from STL, writing a program, and developing an algorithm would be easier! For example: Inserting a node, removing a node, copy str, length of string, swap string,...! It would be great if you know about Rail Signaling basics, and what's the difference between automatic and the traditional ones! Review the very basic formulas about Feedback in linear control systems (stable systems, and unstable systems). Their system is based on communication protocols, you shouldn't be surprised if they ask you about WiFi and networking protocols.